DESCRIPTION: A micro-miniature implantable electrical stimulator has been developed. Utilizing a Radio Frequency (RF) carrier for both power and commands, a number of these devices may be implanted into a patient for functional or therapeutic electrical stimulation (FES/TES) applications. These devices, however, can only receive information from an external controller, they are not able to transmit outbound information. A novel design is proposed to permit both inbound power and control and outbound back-telemetry in these devices. Termed "Suspended-Carrier" operation, the external transmitter suspends its RF carrier momentarily, allowing a short burst of data to be transmitted by the implanted device outbound to the external controller. By this method the weak signal produced by the implanted device is not masked by the comparatively enormous signal of the external transmitter and may be readily received and decoded. This outbound information could include sensor data or operational status data from the implanted device and would be a crucial step in creating closed loop implanted electrical stimulation systems and improving the reliability of FES/TES systems using microstimulation technology. PROPOSED COMMERCIAL APPLICATION: Commercial applications of the microstimulator technology described above could include, but are not limited to, limb advancement in the hemiplegic or paraplegic patient, urinary and fecal incontinence control, hand and upper limb function augmentation or replacement in the stroke and spinal cord injured populations, spasticity control in the hemiplegic, spinal cord injured and cerebral palsy populations, pain suppression, peripheral vascular disease, shoulder subluxation reduction in the hemiplegic patient, and a host of other applications including exercise, range of motion, and contracture reduction in many populations. All of these applications would incur greatly reduced cost, surgical intervention and risk compared to other multichannel implanted electrical stimulation systems. [unreadable]